LOS ANGELES  Signs were hanging Wednesday on the doors and windows at Heritage Hall, the athletics building at the University of Southern California, advertising a meeting next week for potential walk-on football players.

Southern California's Pete Carroll says he won't be afraid to throw newcomers into the fray.

By Dan MacMedan, USA TODAY file

Exactly why was not immediately clear.

After another stellar recruiting season, USC needs more football players like Las Vegas needs more slots.

The Trojans, who had arguably the best recruiting class in the country last year, then used some of those freshmen to win a share of the national championship last season, added another star-studded crop of recruits Wednesday on national signing day.

Once again, there were some analysts ranking the Trojans' group No. 1.

And when the college football preseason rankings come out this summer, there will surely be a lot of No. 1 votes for the Trojans. And a lot of Heisman Trophy talk surrounding junior quarterback Matt Leinart and junior wide receiver Mike Williams.

This is what is called being on a roll. The Trojans, and head coach Pete Carroll, are sitting on top of the college football world, a juggernaut last year with loads of returning contributors (16 returning starters, including both kickers) and young talent lined up behind them, waiting for their chance.

Carroll has a philosophy of throwing the true freshmen into immediate competition with his veterans and, if they earn playing time, he gives it to them.

"I don't want guys coming in saying they look forward to playing when Mike Williams leaves or after Matt Leinart graduates," Carroll said. "I want them to want to play right now. We recruited every guy as a possible contributor this fall."

Carroll practices what he preaches. In 2002 Williams became a star as a true freshman. Last season true freshman runners Reggie Bush and LenDale White and receiver Steve Smith made big impacts.

The Trojans signed 20 players, 16 from high school and four from junior college. And it might not take long to see some exploits from the newest group. Ten of the high schoolers are among analyst Tom Lemming's Top 100. Five of them are among the top 20.

There are 14 high school All-Americans and three junior college All-Americans on the list, which Carroll said was comparable to last year's group and probably is deserving of being ranked the best in the nation.

"I don't know how you can gauge that," Carroll said. "They rate them with stars, and we've got a lot of stars on this group. We'll know more when guys show what they can do."

Carroll went out of state to land arguably the top offensive lineman in the country, Jeff Byers of Loveland, Colo., and the top linebacker in the country, Keith Rivers of Lake Mary, Fla. He also signed Fred Davis, a heavily recruited 6-4 receiver from Toledo, Ohio.

The Trojans' path to success in out-of-state recruiting was paved with the signing two years ago of Williams, who came from Florida and in two years has become one of the biggest stars in college football.

"Mike coming here and the story that he has become helped us, no question," Carroll said.

The other two top 20 players on the Trojans' list are California products, quarterback Rocky Hinds and defensive lineman Jeff Schweiger.

The Trojans didn't really have a lot of urgent needs, but they did lose three starting offensive linemen. That was addressed with the signing of five offensive linemen, including Byers, who some analysts called the best player in the country.